RESUMO

A 350 mg/kg body weight (b.w.) oral dose of uranyl nitrate (UN) caused 100% mortality in mice three days after administration, due to resulting kidney lesions. Mortality decreased 50% after an oral (o) or subcutaneous (sc) dose of bisodic etidronate (EHBP). Given that bone is also a target organ for uranium (U) in acute intoxication, the aim of this work was to study the effect of exposure to a lethal oral dose of UN on endochondral ossification, and the latter's response to EHBP treatment. One hundred male Balb/c mice weighing 25 g were assigned to one of ten groups. Group I served as control. Group II received a lethal 350 mg/kg b.w. oral dose of UN by gavage. Groups III, IV, VII, and VIII received an equal dose of UN immediately followed by a single 500 mg/kg oral dose of EHBP in groups III and VII and a single 50 mg/kg subcutaneous dose of EHBP in groups IV and VIII. Groups V and IX only received a single 500 mg/kg oral dose of EHBP, and groups VI and X received a single 50 mg/kg subcutaneous dose of EHBP. The animals in groups II, III, IV, V, and VI were sacrificed 48 h after the onset of the experiment, whereas those in groups VII, VIII, IX, and X were killed at 14 days. Histologic and histomorphometric studies were performed on the femurs to determine growth cartilage width, bone volume, and metaphyseal bone activity. Our results showed that all growth cartilage and metaphyseal bone histomorphometric parameters were significantly lower in animals exposed to UN at 48 h than in controls. EHPB administration was found to prevent this condition at 48 h reaching similar values to those of controls. Although histomorphometric values did not reach control values at 14 days, they were higher than those of animals exposed to UN at 48 h not treated with EHBP. It is noteworthy that these values also decreased in animals only receiving EHBP at 14 days. Our results show that EHBP effectively ameliorates the adverse effects of a lethal dose of UN on endochondral ossification.

Assuntos

RESUMO

La caries dental es una enfermedad multifactorial que depende entre otras cosas de carbohidratos fermentables para su formación. Objetivo: El objetivo del siguiente trabajo fue realizar un detallado estudio del consumo de hidratos de carbono cariogénico en la dieta de 37 niños de entre 6 y 14 años concurrentes a la atención odontológica en el C.E.S.A.C. Nro.15, los días martes durante el año 2000, y evaluar los conocimientos adquiridos durante los talleres de Educación para la Salud Bucal. Para tal fin se realizaron encuestas a los niños y a sus madres. Resultados: la población presenta en mayor porcentaje frecuencias de consumo de 6 y 7 veces diarias, la oportunidad es mayor en las comidas, los azúcares más frecuentemente consumidos son el azúcar común, las gaseosas, las galletitas dulces y los jugos azucarados; el 40 por ciento de los niños no concurrió a los talleres y el 50 por ciento no sabía qué es un alimento cariogénico. Conclusiones: en la población encuestada prevalecen las frecuencias de consumo de 5, 6 y 7 veces diarias, siendo los azúcares más consumidos los líquidos azucarados. Las golosinas no muestran un alto consumo en relación a otros tipos de azúcares

Assuntos

RESUMO

La caries dental es una enfermedad multifactorial que depende entre otras cosas de carbohidratos fermentables para su formación. Objetivo: El objetivo del siguiente trabajo fue realizar un detallado estudio del consumo de hidratos de carbono cariogénico en la dieta de 37 niños de entre 6 y 14 años concurrentes a la atención odontológica en el C.E.S.A.C. Nro.15, los días martes durante el año 2000, y evaluar los conocimientos adquiridos durante los talleres de Educación para la Salud Bucal. Para tal fin se realizaron encuestas a los niños y a sus madres. Resultados: la población presenta en mayor porcentaje frecuencias de consumo de 6 y 7 veces diarias, la oportunidad es mayor en las comidas, los azúcares más frecuentemente consumidos son el azúcar común, las gaseosas, las galletitas dulces y los jugos azucarados; el 40 por ciento de los niños no concurrió a los talleres y el 50 por ciento no sabía qué es un alimento cariogénico. Conclusiones: en la población encuestada prevalecen las frecuencias de consumo de 5, 6 y 7 veces diarias, siendo los azúcares más consumidos los líquidos azucarados. Las golosinas no muestran un alto consumo en relación a otros tipos de azúcares (AU)

Assuntos

RESUMO

Over the last decade, increasing attention has been focused on the role of the osteocyte in bone remodeling, in view of its demonstrated ability to respond to mechanical and electric stimuli applied to bone. A previous "in vivo" study performed at our laboratory demonstrated that the application of orthodontic forces results in osteocytic lacunae enlargement. To our knowledge there are no data on cell and lacunae response to an inflammatory stimulus in the literature. The aim of this work was to determine whether osteocyte response to an inflammatory stimulus is comparable to that observed under mechanical stress and whether the ensuing cellular changes involve changes in the shape of the osteocyte and/or its lacunae. Three groups of ten male Wistar rats each, 200 to 250 g body weight, were used. Group I served as control. A cotton thread cervical ligature was placed around the first upper molars of animals in Group II, and those in Group III were fitted with an orthodontic appliance designed to exert a force toward palatine. All the animals were killed 24 hours after applying the stimuli. The histomorphometric determinations were measured on the interradicular crest between the two distal roots of the first upper molars. Osteocyte and lacunar volumes were measured and lacunar shape was analyzed. Group II exhibited a dense inflammatory infiltrate and slight resorption of the crest. Group III showed slight resorption of the vestibular wall. The lacunar volume increased in both experimental groups as compared to controls. The cell volume to lacunar volume decreased. These results suggest that osteocytes respond to inflammatory as well as to mechanical stimuli of bone resorption, enlarging lacunae without changes in cell volume.

Assuntos

RESUMO

Over the last decade, increasing attention has been focused on the role of the osteocyte in bone remodeling, in view of its demonstrated ability to respond to mechanical and electric stimuli applied to bone. A previous [quot ]in vivo[quot ] study performed at our laboratory demonstrated that the application of orthodontic forces results in osteocytic lacunae enlargement. To our knowledge there are no data on cell and lacunae response to an inflammatory stimulus in the literature. The aim of this work was to determine whether osteocyte response to an inflammatory stimulus is comparable to that observed under mechanical stress and whether the ensuing cellular changes involve changes in the shape of the osteocyte and/or its lacunae. Three groups of ten male Wistar rats each, 200 to 250 g body weight, were used. Group I served as control. A cotton thread cervical ligature was placed around the first upper molars of animals in Group II, and those in Group III were fitted with an orthodontic appliance designed to exert a force toward palatine. All the animals were killed 24 hours after applying the stimuli. The histomorphometric determinations were measured on the interradicular crest between the two distal roots of the first upper molars. Osteocyte and lacunar volumes were measured and lacunar shape was analyzed. Group II exhibited a dense inflammatory infiltrate and slight resorption of the crest. Group III showed slight resorption of the vestibular wall. The lacunar volume increased in both experimental groups as compared to controls. The cell volume to lacunar volume decreased. These results suggest that osteocytes respond to inflammatory as well as to mechanical stimuli of bone resorption, enlarging lacunae without changes in cell volume.

RESUMO

Over the last decade, increasing attention has been focused on the role of the osteocyte in bone remodeling, in view of its demonstrated ability to respond to mechanical and electric stimuli applied to bone. A previous [quot ]in vivo[quot ] study performed at our laboratory demonstrated that the application of orthodontic forces results in osteocytic lacunae enlargement. To our knowledge there are no data on cell and lacunae response to an inflammatory stimulus in the literature. The aim of this work was to determine whether osteocyte response to an inflammatory stimulus is comparable to that observed under mechanical stress and whether the ensuing cellular changes involve changes in the shape of the osteocyte and/or its lacunae. Three groups of ten male Wistar rats each, 200 to 250 g body weight, were used. Group I served as control. A cotton thread cervical ligature was placed around the first upper molars of animals in Group II, and those in Group III were fitted with an orthodontic appliance designed to exert a force toward palatine. All the animals were killed 24 hours after applying the stimuli. The histomorphometric determinations were measured on the interradicular crest between the two distal roots of the first upper molars. Osteocyte and lacunar volumes were measured and lacunar shape was analyzed. Group II exhibited a dense inflammatory infiltrate and slight resorption of the crest. Group III showed slight resorption of the vestibular wall. The lacunar volume increased in both experimental groups as compared to controls. The cell volume to lacunar volume decreased. These results suggest that osteocytes respond to inflammatory as well as to mechanical stimuli of bone resorption, enlarging lacunae without changes in cell volume.

Assuntos

Assuntos